Studies On The Preparation Of Functional Electrospun Composite Nanofibers And Their Applications In Drug Loading And Environment Analysis

With the development of society, electrospun composite nanofibers become one of the most popular research field. Non-woven fibers with large surface area and abundant porosity are prepared by the electrospinning technology. As a result, the electrospinning technique attract attentions of a large number of researchers. The present study about electrospinning has been turned to the direction from the single-component to prepare composite that between different nano-materials and polymer. However, the study of functional composite nanofibers have been studied not so much on terms of the reported literatures. In this contribution, we developed a new functional electrospun composite nanofibers and silver nanoparticles loaded polymer composite nanofibers. We used the former composites as drug carriers and investigated their ability to drug delivery, at the same time, we studied the enhanced performance of the latter composites as the surface-enhanced Raman substrates. We further explore their applications in the detection of contaminants in the environment. The main contents are listed as follows:1. Synthetic polyacrylonitrile (PAN)/agar composite nanofibers were fabricated by introducing agar during the electrospinning process, and it was found that the nanofibers could be used for efficient, controlled drug release. Hydrophilic drugs such as ampicillin (AMC) were successfully encapsulated inside the agar. allowing the formation of uniform and smooth AMC/agar/PAN composite nanofibers. Cell viability assays showed that the as-prepared agar/PAN composite nanofibers had good biocompatibility, and the antibacterial activity of the designed drug delivery system was investigated against Gram-negative E. coli with a sustained release profile. The good biocompatibility and enhanced thermal properties—as well as the long-lasting antibacterial activity—of these agar/PAN composite nanofiber-containing drugs indicate their significant promise for a variety of potential medicinal applications. We believe that this approach could serve as a model technique in the fields of drug delivery and controlled release when considering the compatibility between polymers and drugs.2. Fairly uniform polymethacrylic acid (PMAA)/poly (N-vinylpyrrolidone)(PVP) ultrafine fibers containing silver nanoparticles (AgNPs) were successfully prepared via electrospun AgNO3/PMAA/PVP solutions by means of in situ photo reduction of silver ions. The presence of PMAA apparently improves the amounts of silver ions in the polymer, because they are liner molecules with abundant carboxyl, which can absorb generous silver ions. As a result, it is high yield of AgNPs in the polymer. The formation of AgNPs has been investigated by different light source. Evaluation of SERS of the electrospun AgNPs/PMAA/PVP fibrous membranes show that the AgNPs in the ultrafine fibers significantly improve the Raman signals. The AgNPs have been reduced by different light source presents differential results on SERS.3. A facile way to make silver nanoparticles (AgNPs) in situ photoreductive on the Agar/PAN nanofibers by the electrospinning technology from metal complex-containing polymer solution. The addition of agar with abundant hydroxyl group sites in the AgNO3/PAN system obviously improves the contents of silver ions in the polymer, and the possible mechanism of this process is proposed. Well-distribution, uniform and small size AgNPs immobilized on Agar/PAN nanofibers were demonstrated as surface enhanced Raman scattering (SERS) substrates. A facile, novel and rapid approach for the determination of malachite green (MG) was demonstrated. The SERS measurement revealed that the minimum detection concentration of MG in water as low as0.1μmol/L with a linear response ranging from0.1～100μmol/L (R2=0.9976).The above experimental results indicated that, the agar were introduced into the polyacrylonitrile system to form a new composite material and used as the drug carriers, which can remarkably improved the drug loading efficiency and obtained a better drug release profile. Also, the hydrophilic drugs can be loaded into the hydrophobic polymers due to the synergistic effect of agar. The current study in this paper is a new addition for the drug delivery system. The AgNPs/PMAA/PVP composite nanofibers were prepared by the doped of polymethacrylic acid (PMAA), which act as the adsorbent of silver ions, resulting both a higher yield and the good dispersibility of silver nanoparticles. This method well solved the problem that the aggregation of nanoparticles. Because of the hydrophilic of PVP. the application of the AgNPs composites were restricted to some extent. On the basis of agar-doped system, according to the established methods, we prepared AgNPs/agar/PAN composite nanofibers, this composite not only remained a good dispersion and high yield of AgNPs, but also water-soluble stablely. This composites can be used as effective surface-enhanced Raman scattering substances to determinate the detriment in the environment.In summary, the research results described above would be important for expanding the loaded drug types of drug delivery systems and improving the methods to prepare the composites contain silver nanoparticles and polymer nanotibers. These methods proposed herein are simple, facile and effective. We hope these will be benefit for further development of functional electrospun composite nanofibers and helpful to expand their applications in a variety of fields.